Green Mountain 5.56 AR-15 Barrel 12.7" M4 A1 Phosphate - GM-M68

Discover the precision and reliability of the Green Mountain 5.56 AR-15 Barrel 12.7″ M4 A1 Phosphate, engineered for tactical shooters and builders seeking a dependable carbine-length option. Crafted from durable 4150 chrome moly vanadium steel with a chrome-lined bore and chamber, this barrel delivers consistent performance in demanding environments while resisting corrosion and wear.

Key Features

• Chrome-lined bore and chamber for extended barrel life and easy maintenance under high-volume shooting
• Phosphate finish provides a rugged, non-reflective exterior that withstands harsh conditions
• M4 profile offers a balanced weight distribution for improved handling and maneuverability in close-quarters scenarios
• 1:7 twist rate stabilizes a wide range of 5.56 NATO and .223 Remington ammunition for optimal accuracy
• Carbine-length gas system ensures reliable cycling with standard AR-15 components
• 1/2×28 muzzle thread pattern allows seamless attachment of suppressors, flash hiders, and other muzzle devices

Specifications

• Barrel Length: 12.5 inches (overall length 12.7 inches)
• Finish: Phosphate with chrome-lined bore and chamber
• Barrel Profile: M4
• Cartridge Compatibility: 5.56 NATO
• Gas Block Journal: 0.75 inches
• Gas System Length: Carbine
• Platform: AR-15
• Twist Rate: 1:7
• Muzzle Thread Pattern: 1/2×28
• Weight: 26.4 ounces

Why Choose This Barrel

This Green Mountain barrel addresses common pain points for AR-15 builders, including the need for a compact yet reliable option that maintains velocity and terminal performance. The M4 A1-style design enhances compatibility with standard uppers and handguards, while the chrome lining reduces fouling for smoother operation over thousands of rounds. Whether building a home defense rifle or a versatile range gun, this barrel provides the durability and precision tactical enthusiasts demand without unnecessary bulk.

Benefits for Tactical Shooters

Enjoy faster target acquisition and reduced fatigue thanks to the balanced M4 profile. The 5.56 NATO chambering ensures broad ammunition compatibility, while the 1:7 twist delivers excellent stabilization for both light and heavy projectiles. Built to mil-spec standards, it offers long-term value through superior materials and construction.

Upgrade your AR-15 build with this premium barrel from Green Mountain, a trusted name in firearms components. Experience the difference in quality and performance today.